Assessment of SARS-CoV-2 Infection among Healthcare Workers of a German COVID-19 Treatment Center.

To date, more than 160 million people have been infected with COVID-19 worldwide. In the present study, we investigated the history of SARS-CoV-2 infection among 3067 healthcare workers (HCW) in a German COVID-19 treatment center during the early phase of the pandemic (July 2020) based on the seroprevalence of SARS-CoV-2 antibodies and self-reported previous PCR results. The results demonstrate a low prevalence of SARS-CoV-2 infection (n = 107 [3.5%]) with no increased risk for employees with a high level of patient exposure in general or working in COVID-19-confined areas in particular. This suggests that the local hygiene standards implemented in our hospital during the first wave of COVID-19 pandemic were effective in preventing patient-to-HCW transmission. No evidence for highly mobile staff serving as a vector for SARS-CoV-2 transmission could be found. In addition, impairment of smell and/or taste was strongly associated with SARS-CoV-2 history.

Beta-trace protein in ascites and pleural effusions: limits of CSF leakage detection.

Rhino- and/or otoliquorrhea can be diagnosed by detecting beta-trace protein (ß-TP) in nasal or ear secretions, as ß-TP is found in high concentrations in cerebrospinal fluid (CSF) but not in serum. CSF fistulae following trauma or surgery can also occur at other anatomical sites, resulting in CSF leakage into the thoracic and abdominal cavities. By analogy, determination of ß-TP has also been used to diagnose CSF admixture in pleural effusions and ascites. However, no systematic study has yet evaluated the concentrations of ß-TP in such fluids in the absence of CSF. To determine the validity of ß-TP determination as a marker for the presence of CSF, we investigated ß-TP concentrations in pleural effusions and ascites without CSF admixture. Patients from whom samples of ascites or pleural effusion and a paired plasma sample were available were investigated. One hundred sixty-four patients were prospectively recruited. ß-TP concentrations were determined by nephelometry. Mass spectrometric proteome analysis confirmed the presence of ß-TP in the samples. Median ß-TP concentrations detected in ascites and pleural effusions (range, 0.014-26.5 mg/L, median 2.29 mg/L) exceeded the corresponding plasma concentrations 2.6-fold. According to cutoffs published to diagnose rhino- and otoliquorrhea, between 6.1% and 95.7% of the specimens would have been erroneously rated CSF-positive. Protein analysis confirmed the presence of ß-TP in pleural effusion and ascites. Ascites and pleural effusion contain high concentrations of ß-TP that exceed the levels in corresponding plasma. Therefore, ß-TP is not a specific marker for the presence of CSF in these fluids.

Outcome of severe lactic acidosis associated with metformin accumulation.

INTRODUCTION: Metformin associated lactic acidosis (MALA) may complicate metformin therapy, particularly if metformin accumulates due to renal dysfunction. Profound lactic acidosis (LA) generally predicts poor outcome. We aimed to determine if MALA differs in outcome from LA of other origin (LAOO). METHODS: We conducted a retrospective analysis of all patients admitted with LA to our medical ICU of a tertiary referral center during a 5-year period. MALA patients and LAOO patients were compared with respect to parameters of acid-base balance, serum creatinine, hospital outcome, Simplified Acute Physiology Score II (SAPS II) and Sequential Organ Failure Assessment (SOFA) score, using Pearson's Chi-square or the Mann-Whitney U-test. RESULTS: Of 197 patients admitted with LA, 10 had been diagnosed with MALA. With MALA, median arterial blood pH was significantly lower (6.78 [range 6.5 to 6.94]) and serum lactate significantly higher (18.7 ± 5.3 mmol/L) than with LAOO (pH 7.20 [range 6.46 to 7.35], mean serum lactate 11.2 ± 6.1 mmol/L). Overall mortality, however, was comparable (MALA 50%, LAOO 74%). Furthermore, survival of patients with arterial blood pH < 7.00 (N = 41) was significantly better (50% vs. 0%) if MALA (N = 10) was the underlying condition compared to LAOO (N = 31). CONCLUSIONS: Compared to similarly severe lactic acidosis of other origin, the prognosis of MALA is significantly better. MALA should be considered in metformin-treated patients presenting with lactic acidosis.

Reference intervals for eight measurands of the blood count in a large population based study.

BACKGROUND: The blood count is widely used in clinical practice. Well defined reference intervals for each measurand are essential for correct clinical interpretation of results. Most previous studies have not been population-based. We therefore calculated reference intervals for several hematological measurands from a sample of the general adult population of Northeastern Germany. METHODS AND RESULTS: We used data from 2967 healthy individuals recruited for the population-based Study of Health in Pomerania (SHIP). Reference intervals were calculated according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI) using the bootstrap method for the age range from 20 to 79 years and, in addition, stratified according to age and gender with both bootstrap and quantile regression procedures. Reference ranges for erythrocytes, hemoglobin and hematocrit increased with age in women but decreased in men. CONCLUSIONS: Our reference intervals were lower than those previously published for erythrocytes, hemoglobin, hematocrit and leukocytes but higher for Mean Corpuscular Volume (MCV) and Mean Corpuscular Hemoglobin (MCH). Different laboratory methods and study populations may lead to disparity in results.

Thyroid disorders in employees of a nuclear power plant.

BACKGROUND: The thyroid gland is a potential target organ for radiation-related damage. The aim of this analysis was to investigate the association between occupational exposure to ionizing radiation and the risk of autoimmune thyroid disease as well as thyroid nodules and dysfunction in workers of a former nuclear power station. METHODS: Seventy-one male power station workers 38 to 57 years of age who had been exposed to a lifetime dose in the upper allowed range (accumulated lifetime dose 70 to 400 mSv) were compared to a population-based sample of 670 males who were not exposed to occupational radiation. Thyroid ultrasound was performed by the same observers. Laboratory parameters were analyzed in a central laboratory. RESULTS: After controlling analyses for age and further relevant confounders no significant differences with respect to thyroid nodules and markers of autoimmune thyroid disease were detected between exposed and nonexposed individuals. However, nuclear power plant employees had higher odds for elevated serum thyrotropin (TSH) levels than the reference group (odds ratio 4.54; 95% confidence interval 1.43; 13.91). CONCLUSIONS: Workers of a nuclear power plant with occupational exposure to ionizing radiation within the upper allowed dose range have an increased risk of elevated serum TSH levels. Further studies are required to confirm possible effects of occupational exposure to radiation on thyroid function.

Bilirubin measurement for neonates: comparison of 9 frequently used methods.

OBJECTIVE: High blood concentrations of bilirubin are toxic to the brain and may cause kernicterus. Therefore, determination of bilirubin levels is performed for many newborns, and several different methods are available. We compared 9 frequently used methods for bilirubin determination among newborns under routine conditions, to define their sequence of use. METHODS: In a prospective study, bilirubin concentrations were determined with 9 different methods, ie, 3 skin test devices, 3 nonchemical photometric devices (including 2 blood gas analyzers), and 3 laboratory analyzers. RESULTS: A total of 124 samples were obtained. All 3 laboratory methods showed very strong correlations with each other, and their means were used as comparison values. To these comparison values, the skin test devices had correlation coefficients between 0.961 and 0.966, and the nonchemical photometric devices between 0.980 and 0.994. Bland-Altman plots demonstrated good agreement with the comparison values for all nonchemical photometric devices. All skin test devices and 1 nonchemical photometric device underestimated bilirubin levels, particularly at high concentrations. CONCLUSIONS: In the routine care of newborns, the first method for bilirubin testing should be a skin test. If the skin test result exceeds 200 micromol/L and other analytes are to be determined with a nonchemical photometric device, then bilirubin can be included in this analysis and the result trusted up to 250 micromol/L. If the skin test result exceeds 200 micromol/L and only bilirubin concentrations are needed, then a standard laboratory method is the first choice, to avoid repeated blood sampling. Bilirubin concentrations from nonchemical photometric devices that exceed 250 micromol/L should be confirmed with standard laboratory methods.

Methods for the monitoring of direct thrombin inhibitors.

Direct thrombin inhibitors are available for prophylactic as well as therapeutic purposes. Application of hirudin in therapeutic doses has been shown to require drug monitoring. Currently, most experience is available for recombinant hirudin, but the principle aspects of drug monitoring are the same for all direct thrombin inhibitors. Most frequently, activated partial thromboplastin time (aPTT) and modifications of the activated clotting time (ACT) have been used for the monitoring of hirudin therapy. However, these methods are insensitive at plasma levels higher than 0.6 mg/L of hirudin, so that overdoses may be missed despite monitoring. Correlations between ecarin clotting time (ECT), enzyme immunoassays, and chromogenic substrate assays on one side and global tests on the other side are poor. Fully automated chromogenic substrate-based assays, also available as point-of-care tests (POCT), are more precise and sensitive and are not disturbed by interferents such as heparin and antithrombin. Good correlations can be observed between chromogenic assays and the ECT performed in plasma or whole blood samples. ECT can also be determined with POCT systems. Test characteristics such as imprecision and measuring range are comparable to those of the chromogenic assays. In conclusion, therapy with direct thrombin inhibitors should be monitored with chromogenic assays or ECT.